private bool ParseOperand(Lexer lexer, Token token, Attributes attributes)
{
var successfullyParsed = true;
if (token.Is(TokenType.LeftParenthesis))
{
successfullyParsed &= Parse(lexer, lexer.GetNextToken(), attributes);
ValidateToken(lexer.GetCurrentToken(), TokenType.RightParenthesis);
}
else
{
Expression tree = null;
if (token.Is(TokenType.LiteralNumber))
{
tree = new LiteralNumberExpression(Convert.ToInt16(token.Lexeme));
}
else if (token.Is(TokenType.LiteralBoolean))
{
tree = new LiteralBooleanExpression(Convert.ToBoolean(token.Lexeme));
}
else if (token.Is(TokenType.Identifier))
{
var identifierName = token.Lexeme;
token = lexer.GetNextToken();
if (token.Is(TokenType.LeftSquareBracket))
{
successfullyParsed &= ParsePositionInArray(lexer, attributes, identifierName, out tree);
}
else if (token.Is(TokenType.LeftParenthesis))
{
successfullyParsed &= ParseFunctionCall(lexer, attributes, identifierName, out tree);
}
else
{
successfullyParsed &= ParseVariableOrConstantOrParameter(lexer, attributes, identifierName, out tree);
UpdateExpressionAttribute(attributes, tree);
return(successfullyParsed);
}
}
UpdateExpressionAttribute(attributes, tree);
}
lexer.GetNextToken();
return(successfullyParsed);
}
private bool ParseVariableOrConstantOrParameter(Lexer lexer, Attributes attributes, string identifierName, out Expression tree)
{
var environments = attributes["ENVS"] as Environments;
// SEM: Verifico que exista un identificador en los entornos.
if (environments.ExistsLocal(identifierName))
{
var localReference = environments.FindLocal(identifierName);
var local = environments.GetLocal(localReference);
if (local != null)
{
// Las constantes se traducen directamente a los literales correspondientes.
if (local.IsConstant)
{
if (local.Type == DataType.Integer)
{
tree = new LiteralNumberExpression(Convert.ToInt16(local.Value));
}
else
{
tree = new LiteralBooleanExpression(Convert.ToBoolean(local.Value));
}
}
else
{
var identifierExpression = new IdentifierExpression();
identifierExpression.Name = identifierName;
identifierExpression.Reference = localReference;
identifierExpression.Type = local.Type;
tree = identifierExpression;
}
}
else
{
tree = null;
}
}
else if (environments[0].ExistsParameter(identifierName))
{
var parameterReference = environments[0].FindParameter(identifierName);
var parameter = environments[0].GetParameter(parameterReference);
if (parameter != null)
{
var identifierExpression = new IdentifierExpression();
identifierExpression.Name = identifierName;
identifierExpression.Reference = parameterReference;
identifierExpression.Type = parameter.DataType;
tree = identifierExpression;
}
else
{
tree = null;
}
}
else
{
LogIdentifierNotFound(identifierName, lexer.GetCurrentToken());
tree = null;
return(false);
}
return(true);
}
